Maligaya High School Ilang-ilang St., Maligaya Park Subd. Brgy. Pasong Putik, Quezon City Environmental Pollution Caused by Heat Engines A Project Submitted As Partial Fulfillment of The Requirements in Physics Submitted by: Diane Rose Ann Lagrama IV-Rizal January 14, 2010 Submitted to: Mr. Geronimo Fiedalan 2 HEAT ENGINE Performs the conversion of heat energy to mechanical work by exploiting the temperature gradient between a hot "source" and a cold "sink". Heat is transferred to the sink from the source, and in this process some of the heat is converted into work. Examples of Heat Engine: Heat Engine Diagram a) steam engine - a heat engine that performs mechanical work using steam as its working fluid. b) diesel engine – an internal combustion engine A that uses the heat of compression to initiate ignition to bum the fuel. c) petrol engine – an internal combustion engine B w/ spark-ignition, designed to run on gasoline and similar volatile fuels. C d) stirling engine – operates by cyclic compres- sion and expansion of air or other gas. e) drinking bird toy – a toy heat engine that D mimic the motions of a bird drinking from a fountain or other water source. f) heat pump – a machine or device that moves E heat from one location to another location. g) refrigerator – transfer heat from it to the F external environment, cooling the contents to a temperature below ambient. M h) gas turbines – extracts energy from a flow of Combustion gas. Environmental Problems Involving Heat Engines H G 3 Three sources of emittants from engine: A. Fuel tank emit fuel vapours B. Crankcase gives out the partly burnt air-fuel mixture blown off through the piston rings C. Exhaust pipe Pollutants from incomplete combustion: A. gaseous 1. Unburnt hydrocarbons (UHC) 2. Carbon monoxide (CO) 3. Nitrogen Oxides (NOx) B. particulates 1. Soot particles 2. Soluble organic fraction Thermal Pollution Usually associated with increases of water temperatures in a stream, lake, or ocean due to the discharge of heated water from industrial processes, such as the generation of electricity. Increases in ambient water temperature also occur in streams where shading vegetation along the banks is removed or where sediments have made the water more turbid. Both of these effects allow more energy from the sun to be absorbed by the water and thereby increase its temperature. There are also situations in which the effects of colder-than-normal water temperature may be Observed. Small chronic changes in temperature can also adversely affect the reproductive systems of these organisms and also make them more susceptible to disease. Cold water contains more oxygen than hot water so increases in temperature also decrease the oxygen-carrying capacity of water. Car Exhaust Pollution 4 The personal automobile is the single greatest polluter, as emissions from a billion vehicles on the road add up to a planet-wide problem. Driving a private car is a typical citizen's most air polluting activity. The negative effects of automotive emissions are maximum when you sit in traffic surrounded by cars, their engines idling. Everyone in a traffic jam is getting poisoned. The Combustion Process, Gasoline and diesel fuels are mixtures of hydrocarbons-made of hydrogen, oxygen and carbon atoms) Hydrocarbons are burned by combining with oxygen. Nitrogen and sulphur atoms are also present and combine with oxygen when burned to produce gases. Automotive engines emit several types of pollutants. Marine Engine Pollution Fuel from outboard motors in the primary cause of Federal impaired water body designations. Most boaters are aware that engine emissions can produce ground-level ozone and smog. Ozone is a recognized respiratory system irritant that causes lung and heart inflammation. Products of combustion include the greenhouse gases carbon dioxide (CO2) and carbon monoxide (CO). Carbon dioxide is seen as a major contributor to global warming. Flue Gas It is discharged into the atmosphere trough an exhaust pipe, flue gas stack or propelling nozzle. In spark-ignition engines exhaust gas from an internal combustion engine whose fuel includes nitro methane, contains nitric acid vapor, which when inhaled causes a muscular reaction making it impossible to breathe, and people exposed to it should wear a gas mask. They produce smaller quantities of toxic pollutants than petrol and diesel engines of the same power.